Potentiation by deprenil of 1-dopa induced circling in nigral-lesioned rats.
1-Deprenil, a potent inhibitor of type B monoamine oxidase, was a weak inhibitor of 3H-dopamine uptake as well as a weak releasing agent for previously accumulated 3H-dopamine in rat neostriatal tissue slices. In similar experiments d-amphetamine as approximately 100 times as potent as 1-deprenil as a releasing agent. When deprenil (20 mg/kg IP) was given to rats with a unilateral 6-hydroxydopamine lesion of the substantia nigra, it brought about a moderate but long-lasting ipsilateral rotational behavior. 1-Dopa (20-40 mg/kg, IP) by itself caused a considerably stronger rotation in the opposite direction (contralateral). When 1-dopa was given to rats 1 hr after 1-deprenil, there was a considerably greater contralateral rotation than after 1-dopa alone. Clorgyline, a type A monoamine oxidase inhibitor, which by itself at 20 mg/kg caused no rotation, also potentiated the contralateral rotation seen after 1-dopa (5-20 mg/kg). In contrast, d-amphetamine, which by itself caused ipsilateral rotation, failed to potentiate the rotation after 1-dopa. Possible mechanisms for these observations will be discussed.
D000818:Animals; D003010:Clorgyline / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism; D006801:Humans; D006892:Hydroxydopamines / Q000494:pharmacology; D007536:Isomerism; D007980:Levodopa / Q000494:pharmacology*; D008297:Male; D016627:Oxidopamine; D010627:Phenethylamines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012642:Selegiline / Q000494:pharmacology*; D013239:Stereotyped Behavior / Q000187:drug effects*; D013378:Substantia Nigra / Q000502:physiology*
D006892:Hydroxydopamines; D010627:Phenethylamines; D012642:Selegiline; D007980:Levodopa; D016627:Oxidopamine; D003010:Clorgyline; D004298:Dopamine